Per IBF bylaws, the only way Taylor can get out of his mandatory defense is if he plans on fighting a title unification with another champ.
And, while the 27-year-old Jacobs holds the dubious WBA “regular” middleweight championship (under Gennady Golovkin’s “super” world title), this may still qualify as a title unification under the right circumstances (ahem, money).
Both Taylor and Jacobs are advised by Al Haymon, so consider this one “all in the family” as the winner will walk away with two shiny belts. It’s hard to imagine a scenario where Taylor, significantly overmatched in all areas, could be competitive with Jacobs. So, consider this one to be more resume-builder for Jacobs than legitimate showdown.